Field of the Invention
The present invention relates to an image capturing apparatus for generating a moving image having a wide dynamic range by compositing images having different exposures.
Description of the Related Art
Conventionally, a technique for generating an image having a wide dynamic range by compositing images having different exposures has been proposed.
For example, Japanese Patent Laid-Open No. 2013-179584 discloses a technique for compressing images captured by different exposure times to thereby reduce a memory capacity or a DRAM bandwidth relating to composition of these images. In addition, Japanese Patent Laid-Open No. 2013-126181 discloses a technique for generating a high-quality composite image by using a histogram to quickly execute a change of an exposure condition when capturing an image.
However, there are the following problems in the configurations of the foregoing conventional techniques. In the technique disclosed in Japanese Patent Laid-Open No. 2013-179584, because image compression is after a plurality of images having different exposures are acquired from an image capturing element, in image composition for a moving image for which many pixels and a high frame rate is requested, there are cases where transmission of a signal is not timely due to the bandwidth of a transmission channel.
In addition, in the technique disclosed in Japanese Patent Laid-Open No. 2013-126181, although exposure control is performed at the time of capturing, in image composition for a moving image in which many pixels and a high frame rate is requested, there are cases where signal transmission is not timely due to the bandwidth of a transmission channel. In addition, when a transmission channel is used at all times, power consumption increases at a time of moving image capturing, in particular.